Typewriter



.1. wi mag f c. scHLNs TYPEWRITER Filed Jan. 17. 1921 7n venfor.'

Patented Nov. 20, 1923.

UNITED ySh'li l 1,474,917 PATENT orifice.

CARL scHLNs, or THURINGIA, GERMANY, AssIGNoR To MERCEDES Bno- MAscmNnN- UND warrnnwnnxn, or rosr MEHLIs, GERMANY.

TYPEWRITER.

Application led January 17.', 1821. Serial No. 437,985.

(GRANTED Umana 'ma raovisrons orma-E Acr or Manon s, 1921, 41 sur. L., 131s.)

To all whom t 'may concern Be it known that I, CARI. SCHLNS, a citizen of Germany, residing at Zella-Mehlis 2, Thuringia; Germany, have invented certain U new 'and useful Improvements in lypewriters (for which I have tiled applica tions in Germany Mey 1l, 1914, Patent No. 319,752, and on April 2, 1918), of which the following is a specification. This invention relates to improvements in the manner of supporting type-bars for typewriters.

In the hitherto known typewriters, in which the type-bars swing upon a circular arc,.the type-bars stand in the position of rest, and either lie horizontally, or are sus- .pended vertically. They form therefore, in their position of rest, an angle of 90 or 180 .with their point ofA Contact upon the platen.V

- In the position of 90, the type-bars must all be of a certain length, which is limited by the construction of the machine and the standard width of type. IThe length of the type-bars is however so dimensionedthat very soon ili1ttering,and.re'coiling strokes of the type-bars set-in, in consequence of rwhich unclear and obliterated writing is produced.

.that a solid support is impossible, or the type-bars must be extended so far, that the advantage to be gained by the extension of the. angle, is once more lost.

85' All these disadvantages are eliminated by the present invention, if the radius of the axis of oscillation of the type-bars is selected'about the `vertical height of the lower position. of type bar rest from the platen 0 str iling point.. The following advantages If the types are allowed to swing through- B0 180, the tvpe-bars will either be so short,

adjusting of the type-bars by hand, as the type-bars can beused in the condition in which they come from thebending-press- 6. In consequence of shortening the typebars require easier touch control, more rapid action ot' the types ensues, independent of accuracy for the side-guide of the type-bars in the supporting segment. i

7. A considerable reduction in first-cost of the machine in consequence of a more ra.- tional production o the type-bars without special machinery. v v 05 certain standard for type-writing has been introduced. Usually the type bar in standard machines is supported, so that it dej -scribes an angle of from the position of 3Q- rest with respect to the printing point. If 'a bar of half the length should be selected so that the aforesaid angle'should be 180, the angles Y formed by the single-bars at the printing-point c, would be of the `iame value, 85 for the saine space provided'for thetypebar heads. .The position of rest of the typebars would be in the rst case at h, inthe second case at b, Fig. 6.

If at the sam'e angle j at the printing 90 point the distance of the type-blocks from each other is still taken as standard, and

the length of the type-bars is altered,

all possible positions of the type-blocks wlill still remain on the line v -a; The 95 position and angle of the fulcrum center-' and the trajectorv belonging thereto, are correspondingly altered.

4 cases are consequently,possiblenA 10'0 1. l,=90. (Fig. 4) standard machine. 2. #I (Fig. 4) machine with asp'- port of the type-bars with an'angle of 180; s. moonrise. 4. 4:, 9o,but 180 (Figo idea ofthe 1 invention. l

A. Oasell. 'I he difference between the" circular Suppoing-z .A trajectories resulting from the rad11 49.0 mm.

' Otagelaf 3 fw' Thecase 3 is of no interest, as it is the most unfavourable. It is thus shown, that in standard machines,in which the type-bar is 75 mm. and the angle ofswing 90, the circular trajectory which the type-block will have to describe will be 117.8 mm. This is the case als for type-writers, in which the angle of swln is 180 and thel type-block trajectory wou d still be 117.8 mm.

The vertical suspension of the bars at 180 Oilers-therefore no'advantage as the trajectory distance remains they same. But at an angle of swing {3:120"A anda radius=49-5 mm. for Vthe circular arc, the value 103.6 mm. for the trajectory is obtained, viz. a difference compared to cases l and 2, of 14.2 mm. or

A 12% of the distance, which the type-blocks have to pass over. i

All circular. trajectories the centers of which are located on the line e-a produce smaller trajectory values from the printing point c. the shortest trajectory for .the type-block, is theoretically found4 to be for a radius (length of bar) r=42 mm. and an angle of -lswing =140 appertaining thereto.

tory without neglecting the other require- The most favorable case, viz.

and 42mm. with the angles of swing 120 and 150 respectively, is however very small; it is only noticeable for a second position shift of the plates and amounts onlymto" 0.05 mm. as the following calculation shows.

difference thus 0.05 mm.

In practice it is preferable, to select a length of type-bar and an angle of swing, which approximate to the most favourable condition viz.'the shortest circular trajecments for producing a robust machine.

The present -invention relates to typewriters with slot-guides, whereby the bars are guided in Slots of a cast-iron lsegment and whereby the important exchangeability of single type-bars is retained.

In order to meet the last requirement, a working-lever has to fit the slot of the typebar in such wise, that betweeny the bars sufficient space is left for the working-lever andthe rivet belonging thereto.

The tongues, which remain between the slots of the segment, have likewise to be strong enough, so that-they donot bend during milling of the segment. -The thiclrness of the type-bar itselfshould not be 105 more than 1 mm. as its strength is otherwise impaired.

ln consideration of all these requirements it has been found in practice that an angle of 100 to 120 will be most favourable for-a no given length of Atype-bar. The length of the projection orIKg, which the circular trajectory cuts oil at a radius lr about the point al, from the ordinate axis is .found by the formula 115 therefore, as

as the most favorable ratio suitable for prac tice.. I Fhe above specification is based upon In prior `application Ser. No. 35675 iled June 22nd, 1915.. A mo Whats claim as my invention. .and desire to secure by Letters Patent, s.:

1. Illa typewriting machine of l,Substaxn i tially standard proportions in which the' 5 standard vertical distance of approximately 75 mm. is maintained between the prin-ting point and the nesting point of the typeheads, v a platen, sulla type bal', the length of said typebar being substantially two-thirds the `10 vertical distance of the nesting point of the t pe heads from the printing point, said type er being so mounted with respect to said platen vas to swing throu h an are substan- ,t tialy more than 100 an less than 140. l5 2.111 e twpewriting machine of substantaL-y stgndag-d pnoportions in which the vermin distantenf-pproxmtely 75 mmis maintained between the nesting point of the type heads the printing point, a platen and a type ber, sind type bar being zo ,'So amounted with res .Eet t@ Said platen that it ,en angle o? swing from rest of substantially more than.130 and less than 140.

.In testimony whereof I affix my signature g5 in presence of two witnesses.

CARL SCHLNS. Witnesses:

HEINE BEYER, GUBRAND Zumos. 

